Without cheating, you cannot. There is only one of any legendary type in each Pokemon game. Always save before looking for, or encountering a legendary, because if it dies in the battle, it is gone for good.
Pokemon Diamond, Pearl, and Platinum have Arceus.
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Arceus
I think arceus is the the strongest Pokemon in diamond and pearl. Also no moves are supereffective on Spiritomb and arceus
arceus
you get arceus at spear piller
Arceus is not possible to find in Pokemon Ruby. It was released in 2007 with Pokemon Diamond and Pearl
He should be in your PC box. If not check the trade center again.
arceus i believe
Ds action replay.
Technically,yes you can get Arceus in Pokemon Heartgold,but only by trading it to your Pokemon Heartgold game from Pokemon diamond,pearl or platinum.
In the legend of Pearl, Diamond and Platinum, it is indeed said that Arceus is the creator Pokemon, therefore he created Time and Space, and Pokemon.